Epicyclic transmission provided with a lubricating system

Abstract

An epyciclic transmission has a sun gear rotational about a transmission axis, a plurality of planet wheels meshing with the sun gear, and a carrier which supports the planet wheels and is rotational about the transmission axis; the transmission also has a lubricating system provided with at least one nozzle arranged in fixed position, with a collection channel fixed with respect to the carrier and configured to receive a jet of oil exiting from the nozzle, and with at least one pump having a casing fixed to the carrier; the pump is actuated by means of a transmission device in response to the rotation of the carrier to pump the oil from the collection channel to zones on the carrier which require lubrication.

Description

[0001]The present invention relates to an epyciclic transmission provided with a lubricating system.BACKGROUND OF THE INVENTION[0002]As is known, an epyciclic transmission comprises a sun gear, a ring gear and a plurality of toothed planet wheels, which are interposed between the sun gear and the ring gear and are supported by a carrier. A transmission of such a type is capable of transmitting the motion between coaxial shafts rotating at different speeds, and is very effective in providing such a function while maintaining small weight and volumes. Epyciclic transmissions are largely used also in aeronautical engines, for example to transmit the motion to the fan in turbofan engines.[0003]In most applications, the carrier is of static type and is coupled to the fixed structure of the engine by means of a flexible element. Under these conditions, the components supported by the carrier (gears of the planet wheels, possible bearings, etc.) are lubricated without particular difficulty...

AI Technical Summary

Benefits of technology

This solution reduces the risk of oil leakage, minimizes assembly damage risks, and maintains effective lubrication under varying conditions without additional engines, ensuring compactness and balanced rotation, meeting high-pressure and flow-rate requirements in aeronautical applications.

Problems solved by technology

In these cases, a problem occurs when transferring the lubricant oil in an efficient and reliable manner from a static part (typically an oil tank) to a rotating part, i.e. the carrier and the components supported by the same.

The above-described oil transfer systems of known type are not satisfactory due to the high accuracy required when machining and mounting the components which define the aforesaid radial backlash.

Furthermore, during the assembly operation, there is a non-negligible risk of damaging the seals when the sleeve is axially inserted, whereby the correct sealing is compromised.

Moreover, the above-described oil transfer system of known type is not able to compensate for the wear and inevitable variations of relative position between the static part and the rotating part (due to differences in temperature between the start-up conditions and the running conditions, for example).

Furthermore, in current epyciclic transmissions for vehicles, the pressure and flow rate values required for the lubrication and the peripheral speed values of the carrier are relatively high and therefore may compromise the desired sealing, especially when the components are worn.

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